Article of manufacture



UNITED STATES EDWARD W. CLARK, 0F LOS ANGELES, CALIFORNIA.

ARTICLE OF MANUFACTURE.

Specication of Letters Patent.

Patented Nov. 9, 1920.

Application led August 5, 1919. Serial No. 313,262.

To n?? whom it may concern Be it known that I, EDWARD W. CLARK, a citizen of the United States. and a resident of Los Angeles. in the county of Los Angeles and State of California, have invented neu and useful Improvements in Articles of Manufacture. of which the following is a -specilication.

My invention relates to an article of manufacture generally and particularly to a piston for internal combustion engines as an article of manufacture and methods for manufacturing the same. and the main object of this invention is to provide a piston of minimum Weight and maximum efficiency. formed as an integral structure of cast metal. preferably of cast iron and internally reinforced so as to render the head incapable of breakage in ordinary usage due to the shock of the gas explosions in the cylinder.'

It has been demonstrated in practice that in internal combustion engines principally. the stroke being comparatively short, a considerable amount of vibration is set up by the operations of the pistons. and it is an object of this invention to eliminate as much as possible of such vibration by providing a light Weight piston of the character mentioned. thus considerably lessening the energy expended by the engine at each revolution of the crank shaft by decreasing the Weight of the pistons which are lifted thereby. This advantage is more apparent in four cylinder engines than in six cylinder engines, as in the latter the stroke is longer and the vibration is normally less.

Heretofore in pistons of ordinary types a plentiful supply of metal has been usually provided at the head and in the Walls at points Where the greatest strain is had and the benefits of'light weight have been sacri- -ficed for' long life and strength. I have discovered by experiment and practice that an integral piston may be provided having a minimum weight and yet with a substantial reduction in the thickness of the metal around the skirt and in the head by the provision of scientifically arranged and proportioned reinforcing ribs on the inner side of the head and skirt and serving to connect these portions in such a manner that the successive impacts from the gas explosions will be resisted effectively by the head and the strain distributed, so that the life of the piston will not ordinarily be affected. It is Similar characters of reference are em` plo 7ed in the several views of the drawing anc in the specification for indicating the same and like parts.

Referring non', more in detail to the drawing, my improved piston will be seen to embody the usual form of commercial piston,

with the head portion 1, the wall 2, having,

ring grooves 3, 3, therein and rist in bosses 4, 4, being formed integral t erewith, as usual. The casting isso formed that the thicknessof the said head and Wall may be as little as possible and yet be rigid enough for use. a plurality of ribs R, R, etc., being formed at. regular intervals around the interior of the piston which radiate from the center and are tapered from .their upper portions to their lower extremities.

A central depending lug L is formed on the inner side of the head 1, by means of which -the piston may be centered in a lathe or other finishing machine, and an annular rib 5, is formed cncentrcally around said lug for alfording rigidity to the head. The portions r, r, etc., vof the ribs R, R, etc., connect with the concentric rib 5, and taper radially therefrom so as to aford additional rigidity to the head. Other ribs R', and R are provided above the pin bosses 4, 4, and said ribs are substantially wider than 'the ribs R, R, etc., the outer edges thereof being substantially flush with the ends of the bosses, sc that suflicient bracing may be provided at these oints. Below the bosses 4, 4, smaller ri s r', r', are for obvious purposes. t the lower end of the skirt, I provide an annular rib a, which serves to reinforce the bottom of the skirt.

It will be obvious that the system of ribs shown and described will distribute the strain e ually over the piston skirt and head, and that the weakest point, i. e. in the rovided, as shown center of the head, is braced by tapered ribs to the Wall of the piston, thus obviating any breakage at this point due to the explosions in the cylinder. For this reason the thickness of metal at the head may be minimized, and likewise, the thickness of metal around the skirt may be substantially decreased from the ordinary pistons Without decreasing the efliciency or at any point weakening' the iston structure vitally. At the bottom of t e lowest of the rin r grooves 3, a shoulder s is provided whici forms an annula:I rib for reinforcing the wall of the piston.

What I claim is:

As an article of manufacture, an integral structure comprising a circular head member, an annular wall member and o positely disposed bosses extending inwar ly from said Wall member, an annular rib being provided on the inner side of said head member, and a plurality of radially formed ribs connecting said annular rib and said wall member and extended substantially do`wnwardly on the interior of said wall member.

Signed at Los Angeles, Los Angeles county, California, this 30th day 0f July, 1919.

STANLEY S. TURNER, H. M. BRUNDAGE. 

